Elevator cable



Patented Nov. ll, i924.

UNNE

stares WILLARD S. ATKINSON, OF ASHLAND, NEW JERSEY, ASSIGNOR TO ATLANTIC ELE- VATOR COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

ELEVATOR CABLE.

No Drawing.

To all whom, it may concern:

Be it known that I, WILLARD S. ATKINSON, a citizen of the United States, and a resident of Ashland, county of Camden, and State of New Jersey, have invented certain new and useful Improvements in Elevator Cables, of which the following is a specification.

The present invention relates to elevator cables and more particularly to cables intended for use in traction elevator installations of either the wrapped type in which the cable is passed over the driving sheave, thence over an idler and thence led to the counterweight, or the V-groove type in which the cable is simply passed over or about a driving sheave having a V-shaped groove in its surface and thence led to the counterweight.

Hitherto, much difliculty has been experienced in connection with elevators of either of the said types on account of excessive wear of the cables and consequent necessity of frequent replacement, and numerous materials ,have been employed in an efiort to obtain a cable of suitable wear resistant qualities and consequent long .life yet of such nature as to minimize wear on and cutting of the sheaves over which it passes. To this end, cables have been construoted of high carbon steel but in practical operation such cables, while proving of relatively long life, are found not to exhibit the requisite'flexibility and, additionally, to cause a rapid wearing or cutting of the cast iron sheaves with consequent trouble and expense of sheave replacement out of all proportion to the saving efiected through the increased life of the cables; on the other hand, so-called iron cable has been freuently employed, that is, cable in which t e carbon content is in the neighborhood of .10% to .15%, but while with such cables wear on the sheaves is lessened, the wear on the cable becomes excessive with consequent necessity for frequent renewal.

A principal obj ect'of my invention therefore, is to provide a cable of the requisite flexibility, tensile strength and toughness to render the same suitable for employment in traction elevator service while having very great wear resistant qualities and consequent long life but which, under conditions of operatlon, does not cause material wear or cutting of the cast iron sheaves over which it passes, thereby obviating the neces- Application filed December 29, 1922. Serial No. 609,764.

sity for constant replacement of either the cables orthe sheaves which has been necessary with the cables hitherto in use in connection with elevators of this character.

I have found that it is possible to attain the aforesaid objects by constructing the cable of a plurality of suitably twisted wires of relatively low carbon steel containin a given quantity of a suitable metal, pre erably vanadium, thereby producing a very flexible cable of extreme toughness and long life which, as has been proven in practice, may be utilized in conjunction with cast iron sheaves of the V-groove or other type in traction elevator installations without appreciable wear upon the sheaves.

While for the purposes of my invention I may vary the quantitity of the vanadium content of the steel considerably, I find that the carbon content thereof if increased be yond 25% renders the cable substantially unsuitable for the purposes of the present invention, and in the preferred composition of the steel I ordinarily also limit the maximum vanadium content to a similar quantity, namely, 25%, although, as stated, the vanadium content may be varied somewhat from that figure if desired. I also find that the most satisfactory cable is produced when the carbon content of the steel is materially less than the amount mentioned and preferably from .10% to 12%. Thus, for example, I have found in practice that a cable constructed of wires formed of steel of the following analysis gives most satisfactory results and readily accomplishes the object of the present invention:

Vanadium 0.25%

Carbon 0.10% to 0.12% Sulphur 0.02% or lew Phosphorus "0.02% or less exhibiting all of the flexibility and lack of cutting or Wearing effect on the sheaves of the low carbon steel or iron cables of the prior art but with greatly increased tough- .ness and Wear resisting qualities an convator cable formed of a plurality of steel strands having a carbon content of less than 25% and a vanadium content of substantially 25%.

2. As an article of manufacture, an elevator cable formed of a plurality of steel strands having a carbon content of 10% to .12% and a vanadium content of sub- I stantially 3. As an article of manufacture, an elevator cable formed of a plurality of twisted steel strands having substantially the composition carbon .10% to 12%, vanadium 25%, sulphur .O2% and phosphorus .02%.

In witness whereof, I have hereunto set my hand this 28th day of December, 1922.

v WILLARD S. ATKINSON. 

